Mobile communication systems have been developed to provide voice services, while ensuring activity and mobility of users. However, coverage of mobile communication systems has been extended to include data services, as well as voice services, resulting in an explosive increase in traffic and shortage of resources. To meet the demands of users expecting relatively high speed services, an advanced mobile communication system is required.
Requirements of a next-generation mobile communication system include accommodation of increased amounts of data traffic, a significant increase in a transfer rate per user, accommodation of considerably increased number of connection devices, very low end-to-end latency, and high energy efficiency. To this end, there have been researched various technologies such as dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband, device networking, and the like.